Journal of Biosciences最新文献

The constitutive expression of EhLINE1_ORF1p in Entamoeba histolytica cells in the absence of retrotransposition suggests that this protein may serve roles beyond retrotransposition. To delve into this possibility, we generated and analyzed transcriptomic data of EhLINE1_ORF1p partial-knockdown cell lines. This analysis unveiled the significance of EhLINE1_ORF1p in the growth of E. histolytica cells. Our investigation of the consequences of EhLINE1_ORF1p partial-knockdown highlighted its impact on the genes involved in ribosome biogenesis, pre-rRNA processing, RNA helicase, and oxidoreductase activity, particularly those associated with amoebiasis. These affected genes are categorized as having high expression and are essential for optimal cell growth. Validation through western blotting confirmed a substantial and pronounced decline in EhLINE1_ORF1p level, and growth kinetics confirmed decline in cell growth. These findings provide compelling evidence supporting the plausible role of EhLINE1_ORF1p in regulating the growth of E. histolytica.

Plant phenology is the study of the timing and extent of leaf, flower, and fruit production. Phenology data are used to study the drivers of cyclicity and seasonality of plant life-history stages, interactions with organisms such as pollinators, and effects of global change factors. Indices such as the timing of phenological events, and the proportion of individuals in a particular phenophase, seasonality, and synchrony have often been used to summarise plant phenology data. However, these indices have specific utilities and limitations and may be sensitive to sampling methodology, making cross-site comparisons challenging, particularly when data collection methods vary in terms of sample size, observation frequency, and the resolution at which phenophase intensity scores/values are recorded. We used fruiting phenology data from tropical trees across five sites in India to study the effects of sampling methodology on two indices: population-level synchrony (overlap) and seasonality. We supplemented these results with simulations of fast- and slow-changing phenologies to test for the effects of sampling methodology on these indices. We found that the overlap index is sensitive to the resolution of phenophase intensity measurement, with coarser intensity measures leading to overestimation of the overlap index. The seasonality index, on the other hand, was not affected by intensity resolution. Simulations indicated that finer intensity resolution is more important than frequency of observation to accurately estimate population synchrony and seasonality for fast- and slow-changing phenophases. Based on our findings, we provide recommendations for future study designs of tropical tree phenology research, particularly for long-term or cross-site studies.

Hormones such as abscisic acid and brassinosteroids ameliorate stress tolerance in plants. The present investigation demonstrates the importance of brassinolide, an active form of brassinosteroids, in sustaining photosynthesis under high light (HL). The addition of brassinolide to mesophyll protoplasts activates the mitochondrial electron transport chain (mETC), particularly through an alternative oxidase (AOX) pathway. Brassinolide promotes both respiration and photosynthesis, including PSII activity, under HL. Total respiration was enhanced, but brassinolide caused a differential modulation of the components of mETC. The capacity of the AOX pathway was significantly enhanced, while the capacity of the cytochrome oxidase (COX) pathway was decreased in response to brassinolide under HL. Further, the transcripts of alternative oxidase1A (AOX1A) were elevated more than cytochrome oxidase subunit 15 (COX15), and cellular reactive oxygen species (ROS) were raised marginally upon treatment with brassinolide under HL. Brassinolide enhanced the capacity of the AOX pathway in mETC to ensure an optimal cellular ROS, which in turn sustains photosynthesis. Thus, mETC plays an important role in optimizing photosynthesis under HL stress and highlights the potential of brassinolide in enhancing plant stress tolerance.

Plants respond to water scarcity by modifying transcription and metabolite accumulation; however, mechanisms leading to drought tolerance/sensitivity in chickpea (Cicer arietinum L.) are poorly understood. To understand the molecular basis of drought tolerance/sensitivity, the carbohydrate content and transcriptional changes in the genes of sugar, starch, abscisic acid (ABA), and gibberellic acid pathways were studied in a drought-tolerant genotype (ICC 8950) and a drought-sensitive genotype (ICC 3776). Droughts disrupted carbohydrate metabolism in ICC 3776, leading to decrease in starch content and increase in sugar content, including sucrose. In ICC 8950, under drought stress, the starch content remained unchanged but sugar levels increased slightly. The reduction in starch content in ICC 3776 resulted from increased degradation rather than decreased synthesis, whereas in ICC 8950, starch anabolism as well as catabolism genes were downregulated, leading to unchanged starch levels. The increase in sucrose content in ICC 3776 under drought stress resulted from lower degradation due to the downregulation of cell wall invertase. The expression of ABA catabolism genes under drought increased in ICC 3776 but decreased in ICC 8950, suggesting increased ABA content in ICC 3776 but not in ICC 8950. This study showed that drought causes a decrease in the starch content and an increase in the sucrose and ABA contents in the drought-sensitive genotype, whereas the drought-tolerant genotype maintains starch and sucrose levels coupled with lower ABA.

Glyphosate-based herbicides (GBHs) can be found in waterbodies and may affect aquatic populations, resulting in physiological and behavioral impairments. In Colombia, white cachama (Piaractus orinoquensis) are frequently found in areas subjected to glyphosate aerial fumigation. This study aims to investigate changes in c-Fos protein expression in P. orinoquensis telencephalic hemispheres after exposure to 0, 1, 5, and 10 mg/L glyphosate for 30, 60, and 90 min. For this purpose, 5 lm paraffin sections were obtained and used for c-Fos immunodetection. To define the effect of xenobiotics on c-Fos expression, nuclei were taken from the dorsal dorsal (Dd), dorsomedial (Dm), dorsal posterior (Dp), dorsolateral (Dl), ventral (Vv), dorsoventral (Vd), and ventrolateral (Vl) regions of P. orinoquensis telencephalic hemispheres. Except for Dd nuclei, other nuclei showed an initial increase in c-Fos+ cells, followed by a progressive decrease toward values similar to those observed in unexposed individuals. In Dd nuclei, the initial tendency was toward a reduced number of c-Fosexpressing cells, followed by an increase in unexposed values. As changes in the number of cells containing c-Fos can be related to changes in neuronal activity, GBH exposure may potentially affect the fish's behavioral and sensorial performance, resulting in a reduced survival probability in its natural environment.

The capability of neurons to regenerate after injury becomes poor in adulthood. Previous studies indicated that loss of either let-7 miRNA or components of insulin/insulin-like growth factor signaling (IIS) can overcome age-related decline in axon regeneration in Caenorhabditis elegans. In this study, we wanted to understand the relationship between these two pathways in axon regeneration. We found that the simultaneous removal of let-7 and the gene for insulin receptor daf-2 in parallel increased functional recovery involving posterior touch sensation following axotomy of posterior lateral microtubule (PLM) neurons in adulthood. Conversely, the loss of let-7 could bypass the regeneration block due to the loss of DAF-16, a transcriptional mediator of DAF-2. Similarly, the loss of daf-2 could bypass the requirement of LIN-41, a transcriptional co-factor of the let-7 pathway. Our analysis revealed that these two pathways independently control the targeting of the regenerating axon to the ventral nerve cord (VNC), which leads to functional recovery. The computational analysis of the gene expression data revealed that a large number of genes, their interacting modules, and hub genes under the let-7 and IIS pathways are exclusive in nature. Our study highlights a potential to promote neurite regeneration by harnessing the independent gene expression program involving the let-7 and IIS pathways.

Reproductive status influences metabolism and health across the lifespan in diverse ways, and mitochondrial function plays a critical role in mediating this relationship. Using the Caenorhabditis elegans germline ablation model, we investigated the impact of germline stem cell (GSC) loss on mitochondrial dynamics and respiratory function. Our results show that GSC loss reduces mitochondrial volume and respiratory function in young adulthood but preserves mitochondrial activity during aging and upon exposure to hypothermic stress, correlating with enhanced survival. We found that the transcription factor NHR-49/PPARα, but not DAF-16/ FOXO3A, was essential for preserving mitochondrial function and hypothermia resistance in these long-lived mutants. Together, these findings reveal the impact of germline signals on somatic mitochondrial health and underscore the intricate relationship between reproductive fitness and organismal health.

Diabetes involves complex metabolic dysregulation and necessitates approaches such as α-amylase inhibition to moderate postprandial glucose spikes and hyperglycemia. Thus, this study scrutinizes the α-amylase inhibitory potential of selected traditional rice varieties (Athur Kichili Samba, Poonkar, Karuppu Kavuni) as well as a modern variety (CO 43) in the cooked condition, using computational approaches alongside in vitro validation. The 156 metabolites obtained from gas chromatography-mass spectrometry analysis, docked with human pancreatic α-amylase (HPA), and based on the binding energies top-five-ranked metabolites were shortlisted (PubChem IDs: 91714169, 13821354, 167795, 2756016, and 3075922). In addition, molecular dynamics simulation was carried out for a timescale of 200 ns to assess protein-ligand complex stability, with parameters such as root mean square deviation, root mean square fluctuation, radius of gyration, solventaccessible surface area, H-bond, and interaction energy. Furthermore, molecular mechanics Poisson- Boltzmann surface area (MM/PBSA) and molecular mechanics generalized Born surface area (MM/GBSA) analyses were performed to validate the selected inhibitors. In vitro studies corroborated inhibitory effectiveness, with Athur Kichili Samba having the highest potency (IC50=4.48 mg/mL), followed by CO 43, Poonkar, and Karuppu Kavuni (IC50=5.12, 6.29, and 11.35 mg/mL). The consistent ranking of antidiabetic functionality observed across both computational and experimental approaches highlights the potential of these traditional rice varieties, suggesting additional clinical investigations to endorse their global consumption.

The Johanson-Blizzard syndrome (JBS) is a complex autosomal recessive disorder that manifests through a spectrum of symptoms, with deficiencies in the ubiquitin-protein ligase E3 component N-recognin 1 (UBR-1) at its genetic core. Despite its clinical significance, the molecular intricacies of UBR-1's role in JBS remain largely elusive, presenting a formidable challenge in devising targeted treatments. The nematode Caenorhabditis elegans, with its genetic tractability and conservation of fundamental biological mechanisms, emerges as an invaluable model for unravelling the molecular underpinnings of JBS. This review integrates the latest discoveries from C. elegans studies, shedding light on UBR-1's multiple functions: its regulatory impact on cellular pathways and, particularly, its crucial involvement in glutamate metabolism. By assessing the contributions of these studies to our understanding of JBS, this review highlights the potential significance of glutamate metabolic dysfunction in JBS pathogenesis.

Our knowledge of how and why various biological and ecological traits relate (scale) to body size has grown at a rapid pace. In this exploratory analysis, I aim to further advance our knowledge of biological scaling by arguing that individuality and selfhood increase along a size spectrum from tiny microbes to huge trees and whales, as driven by a gradient of decreasing mortality. According to a proposed size-self spectrum (SSS) model, tiny short-lived organisms are continuously engaged in relatively rapid, all-consuming, selfless reproduction, whereas large long-lived organisms have evolved relatively high levels of individuality and selfpreservation. Grades of individuality in organisms along the SSS are recognized by their levels of development of (a) protective boundaries between their inner and outer environments, (b) autonomy and identity preservation, and (c) self-awareness and regulation. Paradoxically, as increasingly large organisms have evolved increased independence from their external environments, they have also exerted greater per-capita impacts on them. With increasing body size, the prevailing direction of influence of an individual organism's internal versus external environments switches from inward in small 'exocentric' species to outward in large 'endocentric' species. Implications of the SSS model for understanding the nature and environmental impact of humans, who are relatively large organisms, as well as various other controversial biological, ecological, and philosophical issues are discussed.